Electronic calculators are very popular today. Miniaturization in dimension has become possible since the development and application of IC, LSI and LCD and the manufacturing cost is greatly reduced. It is well known that key panel operation is indispensible during use of an ordinary electronic calculator, and in order to record during calculation, paper and pen are necessary accessories which sometimes are not available at hand. For larger size desk top type calculators, a paper roll for printing of the record is often provided, and some super-thin size calculators are therefore incorporated with a small pad of paper and a minipen as a pocket-book set for convenience. A commodity so called a calcu-pen has been marketed in the form of an aggregated key-operated calculator and pen. However, independent operations for note taking and calculation are required. More recently, a calculator has been disclosed with an electronic pen connected to the calculator by a conductive lead, instead of conventional key operation, and the pen is used to carryout the calculation. Yet drawbacks remain to be improved upon, since the said electronic pen has to be used with a specifically designed plate or with the aid of certain mediums and the numerals and calculation records can only individually or temporarily appear and can not be kept wholly and permanently.